Piston ring



1947- v. F. ZAHODlAK-IN 2,432, 02

PISTON RING Filed April 23, 1946 2 Sheets-Sheet l INVENTOR. m 3? x ZkmDec. 16, 1947. v. F. ZAHODIAKIN 2,432,502

I PISTON RING Filed April 23, 1946 2 Sheets-Sheet 2 INVENTOR.

Patented Dec. 16, 1947 UNITED STATES PATENTOFFICE PISTON RING Victor F.Zahodiakin, Short Hills, N. J. Application April 23, 1946, Serial No.664,343

This invention relates to piston rings, and is particularly directed tothe oil control type of piston ring. The broad basic purpose of thepresent inventor has been to provide a novel and improved ring whichprovides for circumferential pressure of the ring against the cylinderbore at all points, that is to say, wherein the ring will have uniformengagement'with the wall of the bore and will conform radially to anylocal or general variation in thecontour of the wall. For anunderstanding of the type of ring to which the present improvements aredirected, reference may be made to the patent to Victor F. Zahodiakin,2,397,636, issued April 2, 1946.

Generally speaking, the type of ring referred to is formed from a stripof steel which is stamped or punched and bent to provide segments spacedalong radial lines and connected by a continuous corrugated or loopedstrip, having connecting links supporting the upper and lower crownmembers of the segments. In other words, this type of ring is formed ofa relatively thin strip fabricated to the desired form, and is known inthe industry as a sheet metal ring.

More specifically, it has been the object of the present inventor toprovide a ring of this type which insures a solid and uniform supportbetween the spaced upper and lower crowns. The crowns are uniformlysupported, and at the same time, connected integrally by means of theconnecting links which form the back walls of the segments. In thepresent improvement, the lateral or circumferentially extended portions.of each crown are supported by means of the spring loops which providefor the resiliency of the ring.. These loops are projected outwardlyradially be tween the upper and lower crowns.

The purpose of the inventor has been to connect the upper and lowercrowns of each segment by means of integral links. and to support thecrown portions at their lateral ends by means of the spring loops whichare not integral with the crown portions. As a result of this" structurethe crowns do not become deformed as the ring expands and contractssince the "crown portions are free to slide onthe intermediatesupporting loops.

The crowns cannot-become deformed from their 6 Claims. (Cl. 309-45) thatall excess metal is eliminated and the connecting portions between thesegments are much more flexible. Th crowns are of reduced radialdimension and the connecting loops are of reduced general axial width,being only of sumcient axial dimension at those points required forcontacting, spacing, and supporting the crowns. The spaced crowns ofeach section are supported at three points, integrally at the back andnonintegrally adjacent the radial gaps, or in other words, at thecircumferential ends of the crowns, whereby high velocity of the ringswill not cause the bore contacting edges of the crowns to deform underhigh pressure or friction. If the lateral or circumferential ends of thecrowns are not solidly supported, it is obvious that the high pressureor friction incurred in high speed operation will cause these ends todeflect, with the result that the contact of the cylinder bore will beirregular, which will damage the surface of the bore and which willultimately result in breakage of the crowns and resultant damage to theengine. The present structure completely eliminates the above defectsand results.

Further action of the ring is to break up carbon formation on theinternal surfaces of the crowns, due to the sliding supporting contactwith the loops, the formation of carbon being quite a problem in rudeoil engines such as Diesels; reduce frictic'i losses which would resultfrom irregular cbntact with the cylinder walls; reduce the loss of oil;and eliminate the drag between the piston rings and the cylinder bore.

Other objects and certain advantages will be more fully apparent from adescription of the drawings. in which:

Figure 1 is a top plan view of the improved ring, a portion of the ringbeing shown in full 1 lines and the rest in outline.

' Figure 2 is an enlarged fragmentary view taken from the top plan view,a portion of this view being broken away to show the structure of thering intermediate of the upper and lower crowns.

' Figure 3 is a side view of the fragmentary portion shown in Figure 2.

Figure 4 is a plan view of a portion of the strip from which the ring isformed showing the strip stamped or punched to provide the necessaryformation prior to bending.

Figure 5 is a fragmentary perspective view of a portion of the ring.

Figure 6 is a fragmentary sectional view of a piston taken diametricallyof the piston showing the oil control ring of this invention in positiontherein.

Figure 7 is a top plan view of a modified form of ring, a portion of thering being shown in full lines and the rest in outline.

Figure 8 is an enlarged fragmentary view of a portion of Figure 7, partof this structure being broken away for illustrating the structure ofthe ring intermediate the upper and lower crowns.

Figure 9 is a side view of Figure 8.

Figure 10 is a plan view of a portion of the strip from which the ringof Figure 7 is formed showing the strip stamped or punched to providethe necessary formation prior to bending. I

Figure 11 is a fragmentary perspective view of a portion of the ring.

Figure 12 is a fragmentary sectional view of a piston takendiametrically of thepiston showing the oil control ring of thisinvention in position therein.

Referring to the drawings, a strip of steel from which the ring isconstructed is generally indicated at [5. As illustrated, the ring isstamped or punched to provide integrally and flexibly joined sections orsegments.

Generally speaking, the ring consists of an intermediate portion whichis in the form of a continuous strip l6, providing a series of radiallyextended looped portions l'l, connecting links l8 which extend upwardlyand downwardly from the intermediate portion and, crown portions l9.These members of the ring are shown in flat condition in Figure 4, priorto bending. As the ring is bent the loops I! are formed so as to projectradially outwardly as will be best apparent in Figures 2 and 5.

The connecting links are bent at right angles midway between the crownsl9 and the intermediate strip portion i6, and in finished position thecrowns lie or'rest directly upon the upper and lower ends 20 of theloops. These ends 20 of the loops are notched as at 2|, in order toreduce the amount of metal in the links, thereby makingthem extremelyflexible, and providing appropriate oil clearance passageways.Accordingly, this provides a plurality of supporting surfaces 22, uponwhich the adjacent circumferentially disposed ends of the crowns rest.The radial clearances between the crowns are centered directly above andbelow the bent (portions of the loops, so that the loops may be said tostraddle these clearances and thus provide for the support of theadjacent ends of the crowns.

The crowns iii are of reduced radial dimension. The connecting links l8are also of reduced circumferential width. The junctures of the radiallydisposed ends 23 of the links with the crown portions provide structureswhich are T-shaped in topplan view. Thus it will be apparent that theamount of metal utilized in the effect being skeletonized. At the sametime, the proper proportions of the ring are maintained, that is to say,the elements of the ring are fully supported and the loops have theproper strength and flexibility.

As stated generally heretofore, the upper and lower crowns of the ringare connected integrally at the back bythe links orback portions l8.these links being central of the circumferential length of the crowns.The crown portions themsel es are solidly supported on the upper andlower e ds of the flexible loops. The surfaces 22 which support thecrowns at their respective ends are flat surfaces which are disposed inparallelism to the internal surfaces of the crowns. Thus it will be seenthat the crowns are supported in general at ring is reduced to aminimum. the structure in tends through the flexible loops and theseflexible loops are not in connection with the crowns but are each a partof the intermediate strip portion iii of the ring- The connecting linksI 8 are of uniform width throughout and where they join the crowns smallradii are provided as indicated at 24 in the drawing.

The side walls of the spring loops (Figure 2) are parallel, in otherwords, the loops are U- shaped in'top plan view. This structure providesfor easier flexing of the loops with minimum stress set in the material.Also the structure is easier to make since the loops are open.

In the modified form, as illustrated in Figures 7 to 12. inclusive. thestructure is the same as the main form. except that the connecting linkstructure is modified. In this form two connecting links 25 areprovided. Accordingly, each crown is supported generally speaking, atfour points instead of three. These links 25 constitute the back wall ofthe segments and the spaces 26 between the respective links provide foroil flow to the back of the ring into the oil groove and into theinterior of the piston, Also in the modified form only a singlesupporting extension 22 is shown. This extension is of sufficient lengthto straddle the space between the ring sections and therefore supportsthe" adjacent ends of adjacent crowns.

In both forms of the invention the piston is indicated at 21, the oilring groove at 28, and the passageways from the oil groove to theinterior of the piston at 29. It will be evident that in both formationsthe displacement of oil is unimpaired. The ring is particularlyeffective in permitting rapid displacement of oil due to itsskeletonized form. Despite the light and skeletonized form of the ring,the parallel relationship of the crowns always maintained, that is tosay, there is no 1. A piston ring comprising. a resilient strip of sheetmaterial, said strip of material folded to form circumferentiallyarranged segments, each of said segments including an upper crown and alower crown, and a link connecting said crowns at the inner sidesthereof, said segments spaced apart along radial lines, the upper andlower radial lines being in the same radial plane and, resilient meansconnecting the links being generally of less axial dimension than thedistance between the upper and lower crowns, but including supportingportions supporting the adjacent ends of the circumferentially relatedcrowns.

2. A piston ring comprising, a series of sections each consisting of topand bottom walls and the spaces between the sections. said loopsincluding upper and lower extensions adjacent to the respective ends ofadjacent crowns for supporting said crowns and maintaining theirspacing.

3. A flexible piston ring formed from sheet metal, said ring including aseries of U-shaped sections the arms of which constitute the top andbottom crowns of the ring, loop sections disposed parallel to the axisof the ring, said loop sections having their inner ends formedintegrally with the inner members of the U-shaped sections and theirlooped ends extending outwardly and laterally between the adjacentU-shaped sections, the upper and lower edgesof the looped section beingnotched out to reduce the metal therein and to provide a'plurality ofsupporting surfaces for each crown and further to provide all clearancewhereby the top and bottom walls may slide on the unnotched portions ofthe upper and lower edges of the looped sections as the ring compressesor expands.

4. A flexible piston ring formed from a strip of resilient sheetmaterial and consisting of a series of ci-rcumferentially arrangedsections, each of which includes upper and lower crown portions spacedapart and connecting links at the back, and spring loops interconnectingsaid links, said spring loops disposed outwardly between the spacedcrowns and having their axes parallel with the axes of the ring andcoinciding with the spaces between the sections, said links being ofless axial heighth than the distance between the crowns over the greaterpart of their extent, but including supporting projections having fiatcontacting surfaces on their upper and lower edges at either side of thespaces between the sections for flatly engaging and supporting therespective adjacent circumferential ends of the crowns.

5. A piston ring comprising a strip of resilient sheet material, saidstrip providing circumferentially arranged segments, each of saidsegments consisting of upper and lower crown members disposed inparallelism and connected at the back by means of a pair of connectinglinks, each pair of links being interconnected by a cross link, threspective pairs of links being connected by means of resilient loops,said loops radially disposed between the upper and lower crown members,and supporting the same at their circumferential ends.

6. A piston ring comprising a series of circumferentially arrangedsections, each comprising upper and lower crown portions and a pair ofconnecting links forming the back wall thereof, and a central bodyportion for the ring consisting oi a continuous length of materialincluding loops, said loops extending radially outwardly between thecrowns, and havingportions supporting and spacing the respective upperand lower crowns adjacent the spaces between the sections whereby therespective upper and lower crowns of each section are supported at fourpoints.

VICTOR 1 ZAHODIAKIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,224,338 Bowers Dec. 10, 19402,345,589 Engelhardt Apr. 4, 1944 2,397,636 Zahodiakin Apr. 2, 1946

